This present invention is directed to the fiber optic splicing arts and more particularly to a novel and improved re-enterable splicer for a ribbon fiber or ribbonized fiber optic cable.
One particularly useful and successful re-enterable splicer for optical fibers is shown and described in U.S. Pat. No. 5,121,456 which is commonly owned herewith. This splicer includes a metallic splice element which is assembled from two essentially identical halves and includes a longitudinal channel or groove for receiving an end part of each of two optical fibers to be spliced. The splice element is held within a pair of polymer body halves which function as spring clamps for clamping the splice element halves together about fibers to be held in the groove or channel therein. A passageway is provided for a tool that is to operate the splicer so that a fiber can be inserted into the splicer or removed therefrom. This splicer accommodates a single splice; however, a number of additional problems arise in the case of splicing the multiple fibers of a ribbon fiber or ribbonized optical fiber cable.
Such a ribbonized fiber optic cable generally comprises a plurality of optical fibers (typically twelve in number), each of which is provided with a surrounding buffer and a generally flat profile outer jacket, which is often color-coded. The generally flat profile jackets are coupled together by suitable adhesive means to form a generally flat ribbon-like cable containing a plurality of optical fibers, which are arranged in a parallel and spaced condition.
One problem which arises in splicing together the respective ends of two such ribbonized fiber optic cables is that of properly aligning the individual ends of all twelve fibers of each cable with the corresponding twelve fibers of the other cable. The metallic splice element of the above-referenced U.S. Patent contains only a single channel or groove for accommodating fibers. Moreover, the fibers of the typical ribbonized cable are very closely spaced, such that it is difficult to simultaneously align and retain these multiple fibers with those of another similar ribbonized cable within a re-enterable splicer.
Another problem which arises in the case of the ribbonized fiber optic cable is that of guiding respective cables into alignment with a splicing element such that all twelve of the optical fibers therein align with and enter the splicing element simultaneously, as well as being aligned with all of the fibers of a similar ribbonized cable entering from an opposite end of the splice.
Yet a further problem is that of applying sufficient force to the splicer to maintain all of the optical fibers of two such ribbonized cables in place and in optical alignment within the splicer following their initial entry and alignment. It should be noted in this regard that in a splicer employing two splice halves for, in effect, "sandwiching" together the fibers, there will be forty-eight (48) points of contact when splicing a pair of twelve fiber ribbonized cables. That is, each of the twenty-four fibers of the two cables will have one point of contact with each half of the splicer. It can be calculated that a substantial amount of force is necessary to reliably retain the fibers within the splicer with this many points of contact. It is difficult to make a re-enterable splicer in such a manner as to apply the necessary amount of force for maintaining all of the fibers of two such ribbonized cables in a spliced condition therein.